At a time when most of California’s public colleges and universities are cutting back to deal with sharp funding reductions, at least one small campus is rapidly expanding.

When classes begin later this month at the satellite branch of California State University San Marcos here, the student body will be twice as large as it was in the fall semester of 2010 and approximately four times the size of the inaugural class that entered in January 2009.

The numbers are small. There will be only a little more than 200 students on campus, which offers only upper division and graduate courses, on the first day of classes. But annual growth of 20 percent is projected over the next five years, with unspecified expansion anticipated well after that.

“We’ll be adding more degree programs, more certificate programs,” said Suzanne Lingold, CSUSM’s associate dean of extended learning, who oversees the campus. “Next fall we’ll be adding a bachelor’s in business administration and a master’s in business administration. And we are working with the city, the business community and the health care community to see what other programs they would like us to offer.”

CSUSM’s Temecula campus is the only university outpost between San Marcos, Orange County, Riverside and San Bernardino.

“This is a very underserved population,” Lingold said.

The key to the exponential growth — besides demand — is that the Temecula program’s operations are fully self-supporting. With the California State University system facing a $650 million reduction in state funding for the 2011-12 fiscal year, its 23 campuses are reducing the number of classes offered and leaving faculty positions vacant.

“The only way the university could offer classes up here was through (the department of) Extended Learning on a self-supporting basis, totally funded with the students’ tuition,” said Lingold.

By way of example, the cost of a bachelor’s degree in kinesiology at the Temecula campus is $24,162. The same course work at CSUSM would be $19,788.

“Unit-wise, it’s more expensive, sure,” said Sasha Scofield, 24, who moved from La Mesa to Temecula after getting accepted by the campus.

“But, No. 1, we’re promised we’ll have a bachelor’s degree in two years. They can’t promise you that in San Marcos,” said Scofield, who is getting a bachelor’s degree in kinesiology. “Not having to crash classes, no waiting lists, that makes a big difference.”

CSUSM has offered some classes in Temecula on an irregular basis since 1999, but the degree granting program is less than three yeas old.

“About four or five years ago, our City Council really made higher education its top goal,” said Aaron Adams, Temecula’s assistant city manager. “We believe higher education is the foundation for economic development.

“Cal State San Marcos was out here teaching limited course offerings. We sat down with them to figure out how we could do more. We courted them, we recruited them.”

The city helped the university find space in an office park and paid for the needed improvements. CSUSM started out by offering one degree, an accelerated bachelor’s degree in nursing.